Climate Change is Throwing Queensland’s Flying Foxes Straight Into the Fire
Brisbane’s black flying-foxes shortly after sunset
As someone who is new to the continent of Australia, I was taken aback one night when I witnessed the procession of flying-foxes parading over the Brisbane River. The colony of bats initially appeared to be just another flock of birds meandering across the blue-tinted dusk sky, soaring as they bobbed in between one another. However, as the specks of black approached my balcony, I noticed their leathery wings beating against the cool night air.
Flying-foxes, of the Pteropus genus, are one of the largest species of bats in the world, with some species growing as long as 1.5 meters from wing tip to wing tip. They inhabit the tropics and subtropics of Asia, Australia and parts of Africa, also going by the moniker of fruit bats. Unlike some other species of bats, they must use sight to make up for their lack of echolocation. As a result, their wide-eyes have become their trademark and have helped them take on cultural significance with many indigenous groups of people. Their teeth have even been used as currency for some odd reason.
I have never been to an area where flying-foxes are found, which is why their appearance over Brisbane was so exciting to me, although the locals may barely take notice of such a sighting. Unfortunately, thanks to recent climate events, the existence of one species of flying-fox in northern Queensland may become much more rare.
During a heatwave in the northern Australian city of Cairns in November 2018, hundreds of flying-foxes were dropping out of the sky due to record temperatures. Over 4,000 spectacled flying-foxes were seared when temperatures soared to 42.6 C (108.7 F).
Flying-foxes at Lone Pine Koala Sanctuary
What makes this tragic extreme weather event even more dismal is that spectacled flying-foxes, named after the light patches of fur surrounding their huge eyes, were struggling well before this grueling heat wave. The Australian government lists the species as endangered, having experienced a 78 percent population drop-off between the years 1985 and 2000 due to habitat loss and paralysis caused by the Australian paralysis tick, among other factors. The environmental stress caused by extreme weather events like the recent heatwave is fast becoming this species’ greatest threat.
Although spectacled flying-foxes have not dealt with a heatwave of this magnitude in recent memory, other species of flying-foxes have been similarly decimated in the not too distant past. In 2004, a heatwave even warmer than the 2018 one killed between 5,000 and 7,000 Grey-headed flying-foxes. Most of these bats were less than 4 months of age, wreaking havoc on the whole population.
Cyclones are another extreme weather event that threatens the existence of flying-foxes, destroying the trees that offer the bats the fruit that sustains them. Their fancy for fruit has also led them into conflict with the humans that run fruit orchards. The spectacled flying-foxes are often culled because of their reputations as fruit thieves. And what flying animal isn’t exempt from electrocution from power lines?
The larger theme is the threat of extreme weather events on flying-foxes because they have the ability to drastically diminish the size of a bat population within a matters of days. These events are even more detrimental when they involve an endangered species like the spectacled flying-fox. Our changing climate is continuing to cook up these extreme weather events, and species like the spectacled flying-fox are paying the price.
According to Dr. Sean Maxwell, of the University of Queensland’s School of Earth and Environmental Sciences, extreme weather events are becoming more frequent and more intense, spelling doom for not only spectacled flying-foxes, but also hundreds of other species. A recent study he conducted on the responses of different species after extreme weather events found 31 different cases of local species’ extinction after such extreme weather events throughout the world.
Although climate change is a long-term trend, it is easy to recognize the immediate effects in weather around the world as the world warms. Because of the swift intensity of events like a cyclone or a heatwave, wildlife populations are ill-equipped to survive it, as the thousands of dead flying-foxes in northern Queensland demonstrate. All it took was one heatwave to eliminate almost a third of the population of spectacled flying-foxes. What will happen to these bats, and countless other species around the world, when the storms and heatwaves keep coming, each one stronger than the last?
Sources:
https://www.uq.edu.au/news/article/2018/12/wildlife-struggle-cope-extreme-weather
http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=185
